Effects Of Different NDF Levels On Growth Performance,Caecum Fermentation,Growth Of Digestive Tract And Immune Of Mucous Membrane On Rex Rabbits

The experiment was conducted to investigate the effects with one factor at five dietaryNDF levels on the growth performance, caecum fermentation,growth of digestive tract andimmune of mucous membrane on rex rabbits. The total test was divided into two stages: fromweaning to3-month old,and from3to5-month old. The dietary NDF of five groups were26%、28%、30%、32%、34%. Flowing are results of the experiment:(1)Two hundred weaned Rex Rabbits (similar weight) were randomly divided into5treatments (40replicates per treatment). The trial lasted7days for adaptation, and53days fortest, respectively. The results showed that, Dietary NDF levels had signmcant influences onaverage daily gain(ADG)and feed/gain(F/G)(P<0.05)and no signmcant influence on the dailyfeed intake (ADI)(P>0.05). Dietary NDF levels had significantly influenced fecal nitrogen(FN), digestible nitrogen (DN), retention nitrogen(RN),and DN/IN(P<0.05).The weight andarea of fur were significantly affected by dietary NDF levels (P<0.01). The dietary NDFlevels had significant influence on total VFA cotent(P<0.05). The acetic acid ratioincreased,propionic acid ratio and butyric acid ratio descended with the increase of dietaryNDF,but every treatment had no significant influence(P>0.05). The dietary NDF levels hadsignificant influence on the weight of caecum and relative weights of stomach, small intestineand caecum (P <0.05). The dietary NDF levels had no significant influence on the villiheight,crypt depth and V/C of duodenum(P>0.05),but the villi height and V/C of jejunum andileum were affected significantly by the dietary NDF levels(P <0.05). The dietary NDF levelshad significant influence on the content of SIgA of duodenum and caecum(P <0.05),thequantity of M cell in sacculus was affected significantly by the dietary NDF levels(P<0.05).In conclusion, the appropriate NDF concentration in the diet of weaner to3-month-old growing rex rabbit is30%.(2) Two hundred3-month-old rex rabbits (similar weight) were randomly divided into5treatments (40replicates per treatment). The trial lasted7days for adaptation, and53days fortest, respectively. The results showed that, The dietary NDF levels had no significantinfluence on average daily gain(ADG),feed/gain(F/G) and daily feed intake (ADI)(P>0.05). The nitrogen intake (IN), urinary nitrogen(UN),retention nitrogen(RNand DN/IN(P>0.05). The weight and of fur was significantly affectedby dietary NDF levels (P<0.01). The dietary NDF levels had significant influence on totalVFA cotent(P <0.05)and no significant influence on the ratio of acetic acid,propionic acidand butyric acid (P>0.05). The dietary NDF levels had affected the weight and relative weightof caecum (P <0.05). The villi height and V/C of jejunum and ileum were affectedsignificantly by the dietary NDF levels(P <0.05). The dietary NDF levels had no significantinfluence on the content of SIgA of duodenum, jejunum and ileum(P>0.05), but the contentof SIgA of caecum and the quantity of M cell in sacculus were significantly affected bydietary NDF levels (P<0.05). In conclusion, the appropriate NDF concentration in the dietof3to5-month old growing rex rabbit is28%～30%。...